I have a 10 bins:
bins = [0,1,2,3,4,5,6,7,8,9]
I have a list of 25 values:
values = [10,0,0,14,14,123,235,0,0,0,0,0,12,12,1235,23,234,15,15,23,136,34,34,37,45]
I want to bin the values sequentially into the bins so each value is grouped into its bin:
binnedValues = [[10,0],[0,14,14],[123,235],[0,0,0],[0,0],[12,12,1235],[23,234],[15,15,23],[136,34,34],[37,45]]
As you can see, the number of values in the bin is not always the same, (as len(values) != len(bins))
Also, I have lots of different values lists that are all different sizes. So I need to do this a number of times for the same number of bins, but different lengths of values lists. The above is an example - the real bin size is 10k, and the real len(values) is from ~10k to ~750k..
Is there a way to do this consistently? I need to maintain the order of the values, but split the values list evenly so there is a 'fair' and 'even' number of the values range distributed to each of the bins.
I think I can use numpy.digitize, but having had a look, I can't see how to generate the 'binned' list
Are you trying to split the list into lists of alternating size between 2 and 3 elements? That's doable, then.
from itertools import cycle
values = [10,0,0,14,14,123,235,0,0,0,0,0,12,12,1235,23,234,15,15,23,136,34,34,37,45]
splits = cycle([2,3])
bins = []
count = 0
while count < len(values):
splitby = splits.next()
bins.append(values[count:count+splitby])
count += splitby
print bins
Edit:
Ah, I see what you're requesting... sort of. Something more like:
from itertools import cycle from math import floor, ceil
values = [10,0,0,14,14,123,235,0,0,0,0,0,12,12,1235,23,234,15,15,23,136,34,34,37,45]
number_bins = 10
bins_lower = int(floor(len(values) / float(number_bins)))
bins_upper = int(ceil(len(values) / float(number_bins)))
splits = cycle([bins_lower, bins_upper])
bins = []
count = 0
while count < len(values):
splitby = splits.next()
bins.append(values[count:count+splitby])
count += splitby
print bins
If you want to more variety in bin size, you can add more numbers to splits
Edit 2:
Ashwin's way, which is more concise without being harder to understand.
from itertools import cycle, islice
from math import floor, ceil
values = [10,0,0,14,14,123,235,0,0,0,0,0,12,12,1235,23,234,15,15,23,136,34,34,37,45]
number_bins = 10
bins_lower = int(floor(len(values) / float(number_bins)))
bins_upper = int(ceil(len(values) / float(number_bins)))
splits = cycle([bins_lower, bins_upper])
it = iter(values)
bins = [list(islice(it,next(splits))) for _ in range(10)]
print bins